Ore-concentrator.



UNITED STATES PATENT Erice,

lRA A. OAMMET" AND FRANK E. SHEPARD, OF DENVER, COLORADO.

ORE-CONCENTRATOR.

SPECIFICATION forming part of Letters 'Patent No. 632,892, datedSeptember 12, 1899.

Application filed October 12,1898. Serial No. 693,334. (No model.)

To @ZZ whom/ it 777/603/ conce-fn:

Be it known that we, IRA A. OAMMETT and FRANK E. SHEPARD, of Denver, inthe State of Colorado, have invented certain new and useful Improvementsin Ore-Ooncentrators, of which the following is a description, referringto the accompanying drawings, which form a part of this speciiication.

The object of our invention is to improve the riflied surface of thetables of ore-concentrators, particularly that class ofore-concentrators in which the table is given an endshalie movementwhich agitates and assists in the separation of the values from the sandand tailings and which at the same time produces a progressive movementof the values along the surface of the table in the line of themovement.Itiscustomaryinsomeforins of such tables to provide riffles extendingeither in the line of the movement or at a slight angle thereto and toso incline the surface o f the table that the water flows across fromriitle to riffie transversely, carrying with it the sand and dust of thepulp and leaving in the channels between the rifies the val ues. Thelatter by the progressive effect of the endshake movement are carriedalong between the riiiles and finally fall from the foot of t-he tableinto a suit-able receptacle. Tables have been constructed by which suchriffles terminated on a line oblique to the table, leaving anapproximately triangular area toward the foot of the table, having asmooth plane or unriffled surface. Then the values pass from the ends ofthe ritties onto such smooth unritfled area, there is nothing excepttheir weight to prevent their being carried sidewise with the wash-watertoward the tailings side of the concentrator. In an application filed byus March 29, 1898, Serial No. 675,637, we have set forth the advantagesof tapered raised riflies which taper down along an oblique line andterminate at a specially roughened surface, the roughening formingminute recesses which assist in retaining the values. Vhile such aroughening tends to prevent to a large extent the loss of values alongwith the tailings, such roughened surface does not in any sense guidethe values toward the foot end of the table, and we have discovered thatthe advantages of an unriffled portion toward the foot of the table maybe retained and the disadvantages be gotten rid of by continuing theriffles at a diminished height across such area. to the foot of thetable. The reduced portion of such rfiies should/be so low as not tointerfere with the transverse iiow of the wash-water toward the tailingsside of the table, yet their presence is sufficient to exert a verydecided guiding tendency to the heavier particles which constitute thevalues. These latter are prevented by the low riflies from being carriedtransversely, and they therefore travel in line with the riffles to thefoot of the table.

Having thus briefly outlined the main points ot' the present invention,we will now describe the invention in connection with the accompanyingdrawings and point out several other features which can. be bestunderstood in connection with the drawings.

Figure 1 is a diagrammatic plan View of the table. Fig. 2 is alongitudinal section ou the section plane 2 2 of Fig. 1; and Fig. 3 is aseries of transverse sections on the respective planes A, B, C, D, E,and F of Fig. 1.

Throughout the drawings like reference letters and numerals indicatelike parts.

Certain features, as will be clearly apparent to any one skilled in theart, are exaggerated for the purpose of clear illustration in thedrawings, and the table shows onlyfour riftles, although it will beunderstood that in practice a greater number are employed. By reducingthe number for the purpose of illustration we have sought to bring outthe details more clearly.

The headfend of the table-surface is proi vided with a gently-upwardincline 40, which takes the place of a vertical confining-wall at thatpoint. This incline confines the pulp and water while it is beingagitated without producing a wave along the surface, such as would beproduced at each movement of thel table if the liquid were confined by avertical wall. Preferably also the rifliesll, 13, 15, and 17 areinclined upward at the saine point, as shown in the drawings, so thatthe head portion Gr rises bodily on an incline above the surface of thepulp upon the table. Along the portion H of the table the riflles formvery decided channels l2, 14, and 16 between them, as will be apparentfrom Fig. 3. In the neighborhood of the oblique line IOO O O, however,the rifies taper down nearly to the surface of the table, not mergingtherein, but continuing at a greatly-reduced height through the portionK of the table-surface. In this manner there are formed a number ofchannels l2, l-LL, and 16 between the riffles, which channels have acontinuous and uninterrupted bottom from end to end and have wallsformed by the rifi'ies at rst of a considerable height and thenv of adiminished height. The more elevated portion of the rifiies should notbe reduced abruptly, but preferably tapers for a considerable extent,which we have sought to indicate by shading in Fig. l and which clearlyappears in Fig. 2 at 35 and 37. The riffles should also widen along theportion K to restrict and reduce the width of the channels between them.This widening of the riiiies is clearly shown in the drawings. Thereason for it is that when the pulp reaches the portion K of the tableand when the Water begins to Wash away the sand lying above the valuesthe decrease in the cross-section or capacity of the channelsnecessarily contracts and deepens the layer of material in each, therebythrowing up the sand, to be caught and washed off by the current ofWater. Furthermore, as the concentration proceeds and the sand iseliminated the remaining concentrates occupy less space. Therefore thecapacity of each channel should be diminished proportionally, that theriiicles may extend upward only just through the layer of concentrates.

The pulp delivered from the feed-box onto the portion H of the table issubjected to the agitatiug action. As the water flows over from riflieto riiiie, seeking the lower level at the tailings side of the table, itcarries with it much of the sand and like materials. The values travelalong the channels between the rifiles with much of the tailings untilthey reach the reduced portion of the rifiies. At this point they arepreferably met by the wash-water which iiows obliquely across theportion K of the table, carrying with it nearly all the material, exceptthe values, which are retained by the low rifiies, and leaving thevalues almost free from sand and dust. Itis clear that after the pulphas been stratified on the portion 1I of the table its condition doesnot have to be disturbed by passing around` the end ofabruptly-terminating riffles, and for this reason We prefer to make thelow riftles on the portion K of the table a continuation of and in linewith the ritlles on the portion H. In the broader claims, however, whichfollow this specification we do no mean to restrict ourselves to such afeature of alinement.

In order to give precise instructions in regard to the height at whichit is desirable to make the rifiies for the su rface K, it is necessaryto know the richness of the ore to be treated 5 but, in general, thericher the ore the deeper will be the layer of values or concentrateswhich is passing over the portion K of the table, and the height of theriles on this portion should be such as to extend approximately up tothe top of such layer, and

thus allow the valueless portions of the pulpY to be washed away withthe water with Vthe least possible disturbance of the values. We have,however, in the foregoing given such instructions as will enable theskilled operator to carry out the invention.

Without attempting to enumerate the several variations and modificationsthat may be made in the details of our invention andwithout departingfrom its principles We shall point out in the following claims the noveland characteristic features of our invention'.

We claiml. An ore-concentrating table having riffles,

extending from end to end of the active surface of the tables, the saidriftles being reduced in height toward the foot end, and the IOO fromthe head end of the table, reduced in height along an oblique line orkarea and increased in width toward the foot of the table,

substantially as set forth.

4. An ore-concentrator table, having a seu` ries of substantiallyparallel riffles extending los' from the head end of the table, reducedin height before their termination and continuing at a reduced andsubstantially constant height for a portion of their foot ends,substantially as set forth.

5. An ore-eoncentrator table provided with a series of riflies which areeach of a constant height for a portion of their length and of aconstant but lower height for a portion of their foot ends,substantially as set forth.

G. An ore-concentrator table, provided with a rittled port-ion towardits headv and a low riiiled portion toward its foot end, the latterportion succeeding the former along an oblique line or area,substantially as set forth.

Signed this 30th day of September, 1898, at Denver, Colorado.

IRA A. CAMMETT. FRANK E. SHEPARD. Witnesses:

YV. D. MILLER, XV. C. WEBB.

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